A varactor is a semiconductor diode with properties of a variable capacitor. In particular, a capacitance of the varactor depends on a voltage applied to the varactor. Conventional differential varactors include differential fingers that are connected to opposite terminals for differential inputs (e.g., a direct current (DC) bias). Conventional differential varactors include stripes and contacts in inner spacing between the differential fingers. The stripes and contacts are used in a single-ended varactor to reduce a resistance of the single-ended varactor. In addition, conventional differential varactors include doped regions in the inner spacing between the differential fingers. The doped regions are used as a contact area for a common terminal.